Bladed rotor



March 16, 1965 D. J. CLARKE BLADED ROTOR Filed Sept. 8, 1961 INVEN TOR.

DANIEL J. CLARKE ATTORNEYS United States Patent 3,173,655 BLED RUIOR Daniel J. Clarke, Bay City, Mich, assignor to The Stalker Corporation, Essexviile, Mich, a corporation of Michigan Filed Sept. 8, 1961, Ser. No. 136,877 9 Claims. (Cl. 253-39) This invention relates to bladed rotors for use in compressors, turbines and the like, and to a method of making the same.

The customary designs and procedures for making a multi-stage bladed rotor includes diflicult problems con cerning the locating and the assembling of the parts. Where a unitary or integral drum is employed with the blades extending therethrough, there arises a difficult problem of holding the various parts in their proper relation during the brazing operation in a furnace. This requires elaborate fixturing and further may result in the necessity of scrapping the whole multi-stage rotor if some of the blades or patrs fail to be brazed.

The apparatus and method of this invention eliminates these difficulties by the provision of a plurality of annularly formed cups each of which form individual internesting stages which make up a complete rotor. Each stage of this rotor includes self-aligning and self-supporting components and eliminates the need for elaborate fixturing. Each stage may be individually brazed by fused metal and individually inspected to assure the proper bonding of the pants.

The cups are formed of sheet metal and each has an outer peripheral portion with a joggle formed therein providing for the interfitting or nesting of the stage including the cup with adjacent stages. The stages may then be assembled and fused together as a unit in a furnace. The resulting multi-stage motor of this invention is characterized by a low polar moment of inertia, light weight, and economy of fabrication. The light weight and low polar moment of inertia are in part achieved by the sheet metal fabrication which provides for thinner walls than can be machined economically.

An important object of this invention is the provision of a lightweight rotor as outlined above with a relatively small polar moment of inertia, and a method of making the same.

Another object of this invention is to provide a composite rotor the parts of which are self-positioning and self-supporting for a furnace welding operation.

A further object :of this invention is to provide a multistage sheet metal rotor consisting of a plurality of internesting parts each of which parts constitute an individual stage of the rotor.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings- FIG. 1 is a fragmentary axial section through a multistage rotor constructed according to this invention;

FIG. 2 is a fragmentary vertical section taken generally along the line 22 of FIG. 1;

FIG. 3 is a fragmentary elevational view of one of the stages of the rotor of FIG. 1 showing the blade holes or slots with the blades removed;

FIG. 4 is an enlarged fragmentary detail of a portion of FIG. 1 showing the attachment of one of the blades and the internesting of the cups; and

FIG. 5 is a section through one of the blades taken generally along the line 5-5 of MG. 4.

Referring to the drawings, which illustrate a preferred embodiment of the invention, a rotor ill comprises a plurality of sheet metal cups 12'l'7. Each of the cups is formed with a generally axially, rearwardly extending rim "ice portion 18, and an integral generally radially extending wall 19. Each cup 12-17 has a joggle such as indicated at 20 preferably formed at the forward or smaller diameter of the rim portion 18 so that one cup can be received in part telescopically on or within the rim of an adjacent cup.

Each cup has peripherally spaced blade openings or slots 24 formed in its rim. For instance, the cup 13 in FIG. 3 has a plurality of peripherally spaced blade slots 24 formed therein conforming to the blade sections, in shape. Each blade 26 extends radially inwardly through a slot 24 for support by a sheet metal blade supponting disk 23, as shown in enlarged detail in FIG. 4. The blades 26 conform closely to the adjacent surfaces of the slots 24 to provide proper brazing clearance when the blades are furnace welded in place.

The disks 28 are formed with forwardly extending annular flanges 2d which cooperate with rearwardly extending annular flanges formed as a part of the walls of the cups. The adjacent edges of the fianges 29 and 30 are in contiguous relation in the assembled condition of the cup and disk.

The multi-stage rotor 10 comprises the sub-assemblies 30-35. Each sub-assembly comprises a stage of blades 26, a blade supporting disk 28 and a cup. For instance, the sub-assembly 31 comprises the cup 13, the blade supporting disk 28, and the blades 26 which extend radially through the slots 24 in the rim portion 18 of the cup to straddle the support disk to which they are jointed by fused metal, preferably by high temperature solder commonly known as brazing material.

The means for securing the blades in fixed assembled condition within the individual sub-assemblies 30-35 include legs 4d and 41 of the blade which straddle the disk 28. The blades are preferably located at their inner ends by a small pnong 50 formed on the leg and seated in a hole 52 forming a sort of detent. The projection of the prong into the hole 52 is small enough so that the legs 43 and 41 of the blade 26 can be sprung into place with the prong 56 entering the hole 52. In FIG. 2, it maybe seen that the disk 28 is formed with a plurality of angularly spaced openings 52 within which the blades 26 of the sub-assembly are assembled and held.

Each of the sub-assemblies 3il35 for a rotor 10 is assembled and bnazed separately. This makes possible the complete examination and inspection of each subassembly independently of the others. If one sub-assem bly proves faulty it can be discarded. If the rotor structure was made of an integral drum extending across all the stages, a defective part or joint could cause the scrapping of the whole rotor. With the individual sub-assemblies the possible scrapping is limited to the defective subassembly only.

Another feature of the invention is the relative axial location of the parts without resorting to expensive jigging. To this purpose, the flanges 29 and 30 are extended to bear on one another. After the sub-assembly is brazed a portion of the flanges is cut away as indicated by the dotted portions shown in FIG. 1. This provides an access opening for inspection between the cup and the disk.

The sub-assemblies are positioned axially one on the other by the joggles 20. They are then preferably tack welded in a few points to hold them in position while they are brazed together, preferably in a furnace.

The completed sheet metal rotor drum is made by an indirect process rather than by the conventional process wherein the drum would be drawn or spun in toto from sheet, and the blades and other parts assembled to it. In the indirect method of this invention the drum is assembled from separate cups brazed together. At first examination this appears to be more expensive and heavier,

3. but further study shows that the advantages of self-location greatly outweigh any of the integral drum; which would require elaborate fixturing to hold the parts in proper relation during the brazing operation in a furnace;

In fact suchfixturing would have to be reconditioned after each pass through the furnace. This would entail.

a prohibitive cost; I V

Furthermore, by using a cup construction one of the disks is. integral with the cup (or drum) and requires no fixtun'ng for location or brazing. This integral constructio i'i is the lightest in weight,

inwrardly turned generally radially extending Wall, means in said cups defining a plurality. of peripherally spaced there being one of said detent openings for each of said The assembled rotor may then be suitably secured 1 to a shaft, as indicatedin FIG. 1 wherein the shaft'dfl is formed with ah anilular front hub 61 having a lip portion 62 propdftioned to engage the joggle of the cup 12.. The hr-Ward wall 19 of the cup 12 may be removedby cutting or eliminated, as desired, for this purpose. 7

The back hub 65 of theshaft 60 may be secured to the rotor '10 by means of an annular ring 66 secured to the outer surface of the adjacent disk 28 immediately below the legs of theblades. The hub 65 may be flanged as indicated at 67 to receive a plurality of bolts 68 which extends into the ring 66. Also, an annular closure plate 70 may also be retained by the flanges 66 and the bolts therethrough. to cooperate with a depending ring 71 carried on the assembly 35.

It is therefore seen that this. invention provides a rotor drum structure which is made up of a plurality of subassemblies consisting of individual cups and disks for retaining the blades. The rotor structure, in itself, proa videsin large part of the self-positioning of the blades and other parts, which is important to achieve low cost partic larly during the brazing operation; The'assembledrotor is characterized by a low polar moment of inertia by the utilizatioi'i of sheet metal. which results inrthinner' walls be machined economically.

While the form of apparatusand the method herein deseribedc'onstitute's a preferred embodiment of the in vention, it is to be understood .that the invention "is not limited to this precise form of apparatus and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What isclairned ist i. In combination to formal multi-stage rotor, a plurality or cups stacked axially forming a rotor drum, each cup haying a rim formed with a joggled annular end porties of reduced diameter telescopically received within the edge portion of the adjacent cup and bonded thereto by fused metal, each cup at an end thereof having a generally circular wallextending. radially inward from said rim, a plurality of blade supporting disks spaced axially within said drum, a stage of blades for each said disk,

said blades being of elongated section and peripherally j spaced about said drum outwardly thereof through said blade openings, and rotor blades of elongated section extending through saidblade slots having a leg extending adjacent said disk, each said leg having-a tang formed thereon with said tang received in one of said detent openings to position said blades. in said sub-assembly.

4. In combination to form;a multi-stage rotor, a plurality of. cups stacked together axially forming a rotor drum, each'cup having a joggled annular end portion of reduced diameter telescopically received within the edge portion of the adjacent cup andbonded thereto by fused metal, each cup at an-end thereof having a generally circular wall extending radially inward at the joggled end of said cup, a blade supporting'disk spacedaxially within said cup, a stage of blades for each said disk, said blades being peripherally spaced about said .cup outwardly thereof and extending radially inward to said disk and fixed-thereto, and abuting flange meanso'n said cup and disk defining an axial spacing .therebetween for furnace Welding as a sub-assembly separate from adjacent cups.

5. In combination to form a multi-stage rotor, a plurality of cups stacked together axially forming a rotor drum, each cup having a joggled annular end portion of reduced diameter telescopically received within the edge portion of the adjacent cup and bonded thereto by fused metal, each cup at an end thereof having a generally circular straight sided wall extending radially inward, a blade supporting disk spaced axially within said cup; a stage of rim and extending radially inward to a said disk and fixed thereto, andshaft means at opposite ends of said drum fixed thereto. 7

- 2. A stage of a multi-stage'bladed rotor comprising an annular sheet metal cup having a generally axially extending rim portion and an inwardly turned generally radially extending wall terminating in a rearwardly turned flange,

means in said cup rim portion defining a plurality of peripherally spaced blade openings therein, said rim portion having formed therein a joggle between said openings and said wall'and proportioned for receptionwithin the rim of an adjacent said cup of an adjacent stage for bonding thereto, and a blade supporting disk for said cup having an outer peripheral edge terminating adjacent the inside surface of said rim portion and having a forwardly turned inner flange proportioned to bear on the flange of said cup to define the assembled position thereof.

3. A multi-stage bladed rotor comprising a plurality of sub-assemblies each including an annular sheet metal cup blades for each said disk, said blades being peripherally spaced about said cup outwardly thereof and extending radially inwardly, rearwardly extending annular flange means. provided on said .cup and forwardly extending flange means provided on said disk in abutment with each other defining said axial spacing thereb'etween, angularly spaced openings formed in said disks, and legs: onsaid blades having a portion in engagement'with said disk at said openings. I

. 6. In combination to form a multi-stage rotor, a plurality of cups stacked together axially forming a rotor drum, each cup having a joggled annular end portion of reduced diameter. telescopically received within the edge portion of the adjacent cup and bonded thereto by fused metal, each cup at an end thereof having a generally circular wall extending radially inward at the joggled end of said cup, a blade supporting disk spaced axially within said cup,

a stage of blades for each of said disks, said blades being peripherally spacedabout said cup outwardly thereof and extending radially inward to said disk and fixed thereto,

'rim portion having a generally circular wall at anend thereof extending generally. radially inward, a blade supporting disk received within'said cup and spacedaxially I from said wall, a stage of blades peripherally spaced about said rim portion outwardly thereof and extending generally radially inward to said disk and fixed thereto by fused metal bonding along the side thereof over a substantial radial extent thereof, and fused metal means fixing a plurality of said sub-assemblies together at said rim portions with a portion thereof telescopically positioned against said joggled end portion and bonded together to transmit rotational torque from one said rim portion to said adjacent cup, each said sub-assembly having means defining an opening therethrough to provide for inspection of said bonding before said sub-assemblies are fixed together.

8. A rotor of claim 7 wherein each rim is formed with elongated blade openings and wherein each blade of said sub-assembly is bonded to said rim portion at said open- 1ngs.

9. In combination forming a multi-stage bladed rotor for interchanging energy with a fluid, a plurality of individual rotor sub-assemblies positioned axially in fixed relation, each said individual sub-assembly comprising a cup having a rim portion, said rim portion having a joggled annular end portion of reduced diameter, each said rim portion having a generally circular wall at an end thereof extending generally radially inward, a blade supporting disk received within said cup and spaced axially from said wall, a stage of blades peripherally spaced about said rim portion outwardly thereof and extending general- 1y radially inward to said disk and fixed thereto by fused metal bonding along the side thereof over a substantial radial extent thereof, and fused metal means fixing a plurality of said sub-assemblies together at said rim portions with a portion thereof telescopically positioned against said joggled end portion and bonded together to transmit rotational torque from one said rim portion to said adjacent cup, and shaft means lapping said rim portion of one of said cups and fixed thereto for supporting said rotor.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN COMBINATION TO FORM A MULTI-STAGE ROTOR, A PLURALITY OF CUPS STACKED AXIALLY FORMING A ROTOR DRUM, EACH CUP HAVING A RIM FORMED WITH A JOGGLED ANNULAR END PORTION OF REDUCED DIAMETER TELESCOPICALLY RECEIVED WITHIN THE EDGE PORTION OF THE ADJACENT CUP AND BONDED THERETO BY FUSED METAL, EACH CUP AT AN END THEREOF HAVING A GENERALLY CIRCULAR WALL EXTENDING RADIALLY INWARD FROM SAID RIM, A PLURALITY OF BLADE SUPPORTING DISKS SPACED AXIALLY WITHIN SAID DRUM, A STAGE OF BLADES FOR EACH SAID DISK, SAID BLADES BEING OF ELONGATED SECTION AND PERIPHERALLY SPACED ABOUT SAID DRUM OUTWARDLY THEREOF THROUGH SAID RIM AND EXTENDING RADIALLY INWARD TO A SAID DISK AND FIXED THERETO, AND SHAFT MEANS AT OPPOSITE ENDS OF SAID DRUM FIXED THERETO. 